Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/lib/delay.S | |
3 | * | |
4 | * Copyright (C) 1995, 1996 Russell King | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | #include <linux/linkage.h> | |
11 | #include <asm/assembler.h> | |
6d4518d7 | 12 | #include <asm/param.h> |
1da177e4 LT |
13 | .text |
14 | ||
8adbb371 | 15 | .LC0: .word loops_per_jiffy |
6d4518d7 | 16 | .LC1: .word (2199023*HZ)>>11 |
1da177e4 LT |
17 | |
18 | /* | |
6d4518d7 PT |
19 | * r0 <= 2000 |
20 | * lpj <= 0x01ffffff (max. 3355 bogomips) | |
21 | * HZ <= 1000 | |
1da177e4 | 22 | */ |
6d4518d7 | 23 | |
1da177e4 | 24 | ENTRY(__udelay) |
6d4518d7 | 25 | ldr r2, .LC1 |
1da177e4 | 26 | mul r0, r2, r0 |
6d4518d7 | 27 | ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 |
8adbb371 | 28 | ldr r2, .LC0 |
6d4518d7 PT |
29 | ldr r2, [r2] @ max = 0x01ffffff |
30 | mov r0, r0, lsr #14 @ max = 0x0001ffff | |
31 | mov r2, r2, lsr #10 @ max = 0x00007fff | |
1da177e4 LT |
32 | mul r0, r2, r0 @ max = 2^32-1 |
33 | movs r0, r0, lsr #6 | |
7999d8d7 | 34 | moveq pc, lr |
1da177e4 LT |
35 | |
36 | /* | |
6d4518d7 | 37 | * loops = r0 * HZ * loops_per_jiffy / 1000000 |
1da177e4 LT |
38 | * |
39 | * Oh, if only we had a cycle counter... | |
40 | */ | |
41 | ||
42 | @ Delay routine | |
43 | ENTRY(__delay) | |
44 | subs r0, r0, #1 | |
45 | #if 0 | |
7999d8d7 | 46 | movls pc, lr |
1da177e4 | 47 | subs r0, r0, #1 |
7999d8d7 | 48 | movls pc, lr |
1da177e4 | 49 | subs r0, r0, #1 |
7999d8d7 | 50 | movls pc, lr |
1da177e4 | 51 | subs r0, r0, #1 |
7999d8d7 | 52 | movls pc, lr |
1da177e4 | 53 | subs r0, r0, #1 |
7999d8d7 | 54 | movls pc, lr |
1da177e4 | 55 | subs r0, r0, #1 |
7999d8d7 | 56 | movls pc, lr |
1da177e4 | 57 | subs r0, r0, #1 |
7999d8d7 | 58 | movls pc, lr |
1da177e4 LT |
59 | subs r0, r0, #1 |
60 | #endif | |
61 | bhi __delay | |
7999d8d7 | 62 | mov pc, lr |
93ed3970 CM |
63 | ENDPROC(__udelay) |
64 | ENDPROC(__const_udelay) | |
65 | ENDPROC(__delay) |